The present invention relates generally to collision avoidance and warning systems, and more particularly to a method and apparatus for autonomously controlling vehicle braking during a potential collision situation.
Collision warning and countermeasure systems are becoming more widely used. Collision warning systems provide a vehicle operator knowledge and awareness of objects or vehicles within a close proximity so as to prevent colliding with those objects. Countermeasure systems exist in various passive and active forms. Some countermeasure systems are used to aid in prevention of a collision while others are used to aid in the prevention of injury to a vehicle operator.
Collision warning systems and countermeasure systems currently exist in various forms. Certain collision warning systems and countermeasure systems are able to sense a vehicle or object in the close proximity to a host vehicle and warn the host vehicle operator, such that the operator can take precautionary steps to prevent a collision or injury. Other collision warning systems and countermeasure systems activate passive or active countermeasures such as air bags, load limiting seat belts, or brake control whereby the system itself aids in preventing a collision or injury.
Active countermeasure systems such as brake control systems are used to apply brake pressure when an impending collision has a high probability of occurring. In situations when the operator is not aware of an impending collision the brake control system autonomously decreases the velocity of the vehicle.
Although vehicles containing brake control systems are desired over vehicles that do not because of their added safety enhancement benefits, brake control systems do have several disadvantages. Traditionally, brake control is performed through the use of a brake control system by activating or deactivating brake pressure at a predetermined constant pressure. The activation of brake control in this manner can be perceived by a vehicle operator to be abrupt and uncharacteristic of normal operator driving behaviors.
Additionally, when brake control is being activated the operator may either continue to allow the vehicle to control the brake pressure or disengage the brake control in which case the vehicle is no longer able to apply brake pressure. For this reason the operator has a choice during a potential collision situation. The operator may allow the vehicle to continue to decrease in velocity at the same rate or disengage the brake control system followed by manually applying increased brake pressure. By allowing the vehicle to continue to brake at the same rate the vehicle velocity may not decrease enough to avoid a collision. Alternatively, by deactivating the brake control system, thereby decreasing the amount of available brake time, the vehicle velocity may also not decrease to a velocity so as to avoid a collision. Also, in order for the vehicle to reactivate brake control after the potential collision situation the operator may be required consciously to remember to reactivate the brake control system.
Once more, traditional brake control systems can restrict operator control over the vehicle by requiring the operator to deactivate the brake control system in a situation where the operator chooses to accelerate to avoid a collision rather than brake. In a collision impending situation reaction time is critical, therefore by requiring the operator to deactivate brake control before performing other precautionary measures may decrease the probability of avoiding a collision.
An ongoing concern for safety engineers is to provide a safer automotive vehicle with increased collision warning and safety countermeasure intelligence as to not only decrease the probability of a collision or an injury but also to autonomously control a vehicle in such a manner, as to which a vehicle operator is accustomed to while in a vehicle. Therefore, it would be desirable to provide an improved brake control system as to control a vehicle braking system in a more xe2x80x9cdriverlikexe2x80x9d fashion.
The foregoing and other advantages are provided by a method and apparatus for autonomously controlling vehicle braking during a potential collision situation. A brake control system for an automotive vehicle is provided. The system includes a vehicle sensor complex that generates a vehicle sensor complex signal and an object detection system that generates an object detection signal. A brake controller is electrically coupled to the vehicle sensor complex and the object detection system. The controller in response to the vehicle sensor complex signal and the object detection signal generates a brake ramping control signal. Controller adjusts brake pressure in response to the brake ramping control signal. A method for performing the same is also provided.
One of several advantages of the present invention is that it provides autonomous braking via a brake ramping control signal. Thereby, providing autonomous braking with smooth transitions.
Another advantage of the present invention is that it allows the operator to have continuous control of the braking system during a potential collision situation.
Furthermore, the present invention provides a brake control system that allows brake pressure to be released using several options so as not to increase reaction time due to deactivating the brake control system. Therefore, decreasing the probability of a collision occurring by providing the operator with potentially more time to react and perform appropriate precautionary actions.